UTERINE EMG SPECTRAL-ANALYSIS AND RELATIONSHIP TO MECHANICAL-ACTIVITYIN PREGNANT MONKEYS

The objective is to analyse internal and external recordings of uterin e EMG in order to reveal common features and to assess the relationshi p between electrical activity and intra-uterine pressure modification. Three monkeys participated in the study, one as a reference and the o thers for data. EMGs are recorded simultaneously, internally by unipol ar wire electrodes and externally by bipolar Ag/AgCl electrodes. Intra -uterine pressure is recorded as a mechanical index, Except for delay measurements, parameters are derived from spectral analysis and relati onships between recordings are assessed by studying the coherence, Spe ctral analysis exhibits two basic activities in the analysed frequency band, and frequency limits are defined as relevant parameters for ele ctrical activity description. Parameter values do not depend on the in ternal electrode location, Internal and external EMGs present a simila r spectral shape, despite differences in electrode configuration and t issue filtering. It is deduced that external uterine EMG is a good ima ge of the genuine uterine electrical activity. To some extent, it can be related to an average cellular electrical activity.